In particular in the case of cabriolets, it is customary practice to activate a rear window via separate link kinematics in order, when the top is closed, to permit the vehicle interior to be ventilated by opening the rear window. A separate activation of the rear window can also ensure a space-saving packing size of the top in the open state. A cabriolet-top arrangement of this type is known, for example, from DE 199 40 796 A1.
It is furthermore known from practice, in the case of motor vehicles with a cabriolet top which is designed as a fixed top, to fold the entire top and put it away in a storage compartment arranged in the region of the C-pillar. However, it is not possible here to put away part of the top in order to ventilate the interior of the motor vehicle while simultaneously retaining the rest of the top.
It is known from practice, in addition to the top kinematics driving a foldable pivoting top, to furthermore provide supporting arrangements for the rear window, which is embedded nondetachably in the pivoting top and, in particular, is made of glass, in order to avoid the top sagging due to the weight of the rear window and in order to stabilize the rear window. These supporting arrangements are only detachable if the folding top is to be put away and do not allow any possibility of ventilating the interior of the motor vehicle.
DE 36 07 650 A1 describes a cabriolet which has a rear window which is mounted in a frame, the frame together with the rear window closing the rear window opening in a raised position or opening it up in a lowered position. The change of position of the rear window takes place either via a handle or via a worm-worm gear system, with a pair of levers being fastened at one end to an upper flange of the frame and at the other end to a joint provided on the bodywork, and a second pair of levers being fastened to a lower flange of the frame and to an installation element. The pairs of levers basically define a four-bar linkage. The frame, together with the flat window fitted into it, executes a displacement essentially along a circular radius in order to be put away in a virtually vertical storage position behind the driver's seat. In order to obtain sealing contact against the roof structure, the frame, which imparts the actual rigidity to the rear window, is provided with a heavy, strip-shaped seal which is not provided in the region of the upper edge of the rear window. There is the risk that, under the dead weight of the window and due to vibrations which occur during the course of the journey, the window will gradually shift out of its position without the handle part being actuated. In the case of a motor drive, a separate brake is to be provided for this purpose, which further increases the outlay on the retractable rear window. Furthermore, it is to be noted that the lever protrudes at least partially into the passenger compartment and therefore executes annoying movements in the driver's head region, and that, due to the manner of storing the rear window, a construction of this type is basically only suitable for a two-seater cabriolet.
DE 198 04 101 C1 describes a folding top for cabriolets, in which a rear window rests on the outer side of a cabriolet top with a frame surrounding the rear window, wherein a flap which is provided on the outer frame can assume a position which leads out vertically from the plane of the window and which can be pivoted through 90° in order to be able to be folded behind the cabriolet top parallel to the frame, and therefore to hold the window together with the frame. The window is opened by the flap being pivoted up and the window being swung open outwards through approx. 135° via a piston/cylinder unit, so that the window can be put away with its outer side flat below the boot lid. For this purpose, the boot lid first of all has to be opened, to be precise about additional hinges provided on the rear side, with the rear window having to be of essentially flat design for this purpose. The result is that the rear window in particular cannot be opened during the journey and in particular cannot be partially opened.
DE 197 53 209 C1 describes, in a theoretical manner, a rear window which can be put away and, firstly, in its closed position, is connected to the C-pillars via connecting devices and can be put away into the boot via joints. The joints may involve a four-bar linkage.
DE 196 36 209 C1 describes a folding top for a cabriolet, in which a rear window made of glass or plastic is provided in the top cloth of a rear top part which can be put away independently of a front top part into a top compartment with a lid, with the two top parts, which are movable independently of each other, being mutually secured via a releasable locking arrangement (not explained in detail). Since the two top parts are cloth tops, a locking of the linkage beyond the dead centre position is to assume, in which the internal stress of the top cloth undertakes the mutual locking.
DE 197 46 569 A1 describes a cabriolet top, the rear part of which is divided into a main frame part and a rear frame part, wherein the rear frame part can be folded down in relation to the main frame part in order to provide a space-saving arrangement in the boot. The main frame part comprises the rear window. An actuation. of the rear frame part in order to open up a window opening is not described.
DE 43 20 603 C2 describes a cabriolet, in which a flat window which can be lowered by means of a hand crank or electric motor and which can be lowered and raised in an extension of its level plane is provided in the rear region.
In all of the abovementioned means of activating a rear window of a vehicle, there is the disadvantage that a corresponding kinematic articulation system is linked to the bodywork and takes up a comparatively large amount of construction space.
DE 199 57 427 C1 describes a cabriolet top comprising a fixed top part, a fixed rear part, a top compartment for receiving the top, said top compartment being arranged in a rear region of the bodywork, and a restricted guidance for opening and closing the top. In order to open the top, initially the rear part is pivoted over the top part, the top part and the above piled rear part beeing subsequently pivotable into the top compartment. The restricted guidance comprises a singe lever between the rear part and the compartment bodywork, said lever beeing pin-jointed with the rear part at its first end via a first arcticulation joint and beeing connected with the bodywork at its second end.
DE 102 43 085 A1 describes a cabriolet top comprising a first top part being formed by a fixed roof shell, a second top part being formed by a fixed roof shell, the first top part and the second top part being each pivotable with respect to the vehicle bodywork, and a restricted guidance, the first top part and the second top part being movable by means of the restricted guidance via a common force introduction unit. The flexibility of the guided movement of the roof parts with respect to each other is noticeable increased by means of a mechanic operating control comprised by the restricted guidance, whereat the movement of the second top part can be slowed down with respect to the movement of the first top part via the operating control.
DE 103 44 679 A1 describes a hardtop vehicle roof comprising three fixed roof parts which are supported by the bodywork via an kinematic articulation system and which are adjustable between a closed position, covering the inner compartment of the vehicle, and an opened storage position. The kinematic articulation system is composed by a seven-joint linkage, which connects all three roof parts and comprises three steering joints.
The three last-mentioned publications show vehicle rear windows which are liftable in a vertical direction.
Accordingly, the invention is based on the object of providing a means of activating a rear window which is constructed in a space-saving manner and with simple means.